The use of sizes on glass fibers is well known. Sizes are applied to the surface of glass fibers for several reasons. While sizes are usually applied to the fibers for the purpose of protecting the fibers during processing immediately subsequent to their formation, sizes can also have incorporated into their compositions certain components which impart properties which facilitate their usage. Among these can be such properties as improving strand integrity, impact strength, toughness, elongation at break and, of equal importance, improving the adherence between the glass fiber and the matrix into which the glass fibers or strands may be incorporated for reinforcement purposes.
Relatedly, if the size can be applied to the fibers in some form other than an aqueous solution, in which form most sizes are applied, there can be avoided considerable drying costs and strand discoloration as the size tends to migrate outwardly through the package into which the fibers are wound.
The hot melt sizes of this invention meet these requirements.